Coat of many colours: Harlequin ladybird

The Saving Species team talks to Helen Roy and Richard Comont from the Centre for Ecology and Hydrology about their work on Harlequin ladybird pathogens, and the UK Ladybird survey

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Interviewer

That’s a sound of a lime tree outside the Centre for Ecology & Hydrology here in Wallingford being beaten within an inch of its life, and I’m with Helen Roy looking for Harlequin ladybirds, have we got any Helen?

Helen Roy

We certainly have got some Harlequin ladybirds here having beaten this tree. So we’ve got one just here and this is, so the Harlequin ladybird comes in a variety of different colour forms which can be slightly annoying for people when they’re trying to get sorted with the identification of it. But actually very nicely here we have the two predominant colour forms right by one another. The one that’s the most common is this orange colour form and it’s a big ladybird.

Interviewer

Oh it’s on my finger.

Helen Roy

It is on your fingers.

Interviewer

It’s trying to fly.

Helen Roy

It is flying. It’s a very busy Harlequin ladybird and it is a large ladybird, six to eight millimetres in length. It’s got brown legs if you take a very close look, and this one is orange with lots of black spots and the vast majority of Harlequin ladybirds look just like that.

Interviewer

And what’s this one here?

Helen Roy

Well that’s a Harlequin ladybird as well and as you can see it looks very different, it’s black and it has four red spots and sometimes it will have two red spots. But again it’s big, you can see it’s exactly the same size as the other Harlequin ladybird that we have here. When we get really up close we can see that it has got pale-ish brown legs, so a big ladybird that looks different to the seven spot ladybird because it has the pale legs it’s very likely to be a Harlequin ladybird.

Interviewer

I didn’t know you could have so much fun by beating trees before.

Helen Roy

Oh it’s enormous fun.

Interviewer

We’ve got no shortage of Harlequin ladybirds here beating this tree. How well are they doing at the moment?

Helen Roy

Harlequin ladybirds are having an extremely good year this year and I’m really pleased to introduce so my PhD student Richard Comont who’s extremely busy as well working on these Harlequin ladybirds out in the field.

Interviewer

So what does your study involve Richard?

Richard Comont

It’s looking at the impact that the Harlequin ladybird is having on all of our native ladybird species. So I spend an awful lot of time out in the fields and Harlequins are just everywhere this year, it’s really noticeable.

Interviewer

When the Harlequin ladybird arrived it was seen as a dire predator, something that was going to have a severe effect on native species. Has that come to pass?

Richard Comont

It certainly seems to be. The Harlequin is a really, really voracious species, it eats more or less anything it comes into contact with and it lives in a really huge variety of habitats, it’s the most habitat-diverse species that we have in this country and it’s more than happy to eat virtually anything. It’s recorded eating more than 50 different species of other invertebrate as well as plants and fungi and various other unexpected things like that.

Interviewer

Have we got any evidence though that the Harlequin ladybird is reducing numbers of any native species of ladybird?

Richard Comont

It’s looking increasingly likely. In the New Ladybird Atlas we’ve reported 20 year trends of all the native species and there are a couple of species that are declining in that, but also some work that we have currently underway looking at declines since the arrival of the Harlequin compared to before the arrival show that several species are declining more rapidly, particularly the two spot, which is the species we’re particularly worried about.

Interviewer

Yeah. This is one I used to see in my garden quite a lot and it’s very distinctive, because it just has those two spots, one on each wing case and I’m not seeing them at all now, in fact they’ve been quite hard to find this year. Is that something that’s being mirrored across the country?

Richard Comont

That’s a story that, yeah, is being repeated, virtually all of the recorders that we have have reported far fewer two spots, it’s been noticeable.

Interviewer

By contrast the seven spot ladybird, which is the one that I suppose everybody’s most familiar with that seems to be doing quite well this year, so do Harlequins seem to be having an effect on that?

Richard Comont

Not a major effect. The Harlequin and the seven spot are roughly the same sort of size so there’s not quite such a predation pressure on the seven spot as there is on smaller species like the two spot.

Interviewer

So the effects of the Harlequin seem to be selective, they seem to be quite patchy, is it still on the march though?

Richard Comont

Very much so, yes. Just in the last week we’ve had our most westerly reading record down in Cornwall, they’re also spreading further north, so we’ve had lots of reading records from Scotland so far this year. It’s still forging out at the range boundaries, but also filling in behind them quite rapidly, so getting to really high population abundances.

Interviewer

Gardens are where most people will notice them I suppose.

Richard Comont

It is largely a suburban species, but it does seem to be gradually spreading out into the wider countryside, we’ve had quite a lot of records from, well, from the middle of nowhere effectively from the middle of ancient oak woodlands and such like things where you wouldn’t necessarily expect to find it quite as much, but it really is a generalist, it’s more than happy to live anywhere there’s sufficient food.

Interviewer

Now I know a lot of our ladybirds are subject to parasitoids, small wasps or whatever, which actually invade them and kill them. Does the Harlequin ladybird have any predators in this country?

Richard Comont

That’s something that we’re actually working on quite intensely at the moment with a public participatory survey as well, the UK Ladybird Parasitoid Survey. So, personally I spend a lot of time over the summer collecting ladybird pupae, which is the main parasitoid stage, and the Harlequin is definitely gradually being colonised by native parasitoids. We’ve had four or five different species recorded from it and the percentage is seen to be gradually going up. This year in my studies there’s about 2% parasitism of Harlequin pupae mainly.

Helen Roy

That adult parasitoid, this little conid wasp, it doesn’t have a common name, but it’s a little wasp and it attacks adult ladybirds and it’s one that everyone can look out for, because it forms a lovely fluffy cocoon underneath the adult ladybird, so it’s very charismatic in its own right and we’d really love to hear about the parasitoids that people see when they’re out and about looking for ladybirds.

Interviewer

So what does this cocoon look like? Yellow or white?

Helen Roy

It looks like a little fluffy seed. It’s sort of a straw brown colour and it forms right underneath the ladybird and very cleverly the parasitoid keeps some of the ladybird intact and so the ladybird twitches over the top of the cocoon and so it gives protection to this parasitoid that is sat underneath it and then out emerges just one adult wasp from this cocoon, but that one adult wasp can lay eggs in maybe 200 new ladybirds.

Interviewer

I mean one question a lot of people will want to know is whether they should kill Harlequin ladybirds or whether there’s any form of natural control in the form of these parasitoid flies or wasps, so two questions there, who wants to answer those?

Richard Comont

We very much don’t recommend that people kill them. They’re a really, really variable species, so for a start it’s quite hard to actually identify that it is a Harlequin for sure, so you’re more than likely to squash a native species and do more harm than good, but also it’s a drop in the ocean. There are so many Harlequins about at the moment that squashing a few here and there will make absolutely no difference to overall numbers. Each female Harlequin can lay 2,200 eggs, so they can just repair that population damage overnight.

Helen Roy

But in terms of whether these little parasitic wasps and flies will actually regulate populations of Harlequin ladybirds is a very difficult question to answer. We don’t have any evidence from the past that parasitoids are particularly good at regulating their ladybird host. We see in some sort of localities that they do, there can be maybe 75% of the ladybirds succumb to infection by the parasitoid, but in other areas you don’t get any at all, so we don’t really have a good hold on whether they will regulate or not.

Interviewer

The Harlequin ladybird’s only been around for seven or eight years in the UK and it’s a relatively short period of time, so do we think as years go by a natural balance of population will be achieved? In other words Harlequin numbers will flatten out.

Richard Comont

Yeah, almost certainly eventually. That’s what we’ve seen in the other invasive populations in North America and of course what happens in the native range that they do co-exist, but with much smaller numbers than we have currently been used to of our native species.

Interviewer

Helen, as one of the authors of the New Atlas of Ladybirds which was published this year, 47 species included and maps of them all and a huge public participation, what are the trends in British ladybird species generally, are they up or down?

Helen Roy

We’re extremely pleased to report from the 20 year trends that many of the species are quite stable, so the ones that we’re used to seeing, such as the seven spot ladybird is a very stable species. However there are ten species that are declining and that is extremely worrying. And one of them, for example, the 11 spot ladybird that in the 1970s people would’ve seen extremely commonly. It is a red ladybird with 11 spots and it is slightly smaller than the 7 spot ladybird, but some people remember the 1976 ladybird huge boom.

Interviewer

I do.

Helen Roy

And lots of those ladybirds were 11 spot ladybirds, and now it’s so rare that we get an 11 spot ladybird sent to us. I found one at the weekend, but that was my first one for a few years. So the 11 spot ladybird is one that is in decline. Similarly the 14 spot ladybird, but it’s having a very good year this year, but that’s another species that people very commonly would’ve found in their gardens.

Interviewer

This is a little yellow one isn’t it?

Helen Roy

The little yellow one with the square black spots. So I think what’s quite striking from the Atlas trends is the species that have been thought of as being very common and widespread that we’re seeing beginning to decline and that’s what concerns me.

Interviewer

Do you know why they’re declining?

Helen Roy

Well now this is some of Richard’s work in his PhD is beginning to look at these declines and trying to tease out effects of climate change, land use, the arrival of new species, so all of these things just as they have an influence on other insect populations are likely to be affecting ladybirds and some are winning and some are losing.

Interviewer

What about ladybirds that are increasing? Apart from the Harlequin are there any of our native species which are doing quite well?

Helen Roy

Well the orange ladybird’s been extremely exciting in terms of the numbers that we’re getting reported to the online survey, and not just numbers in terms of records in particular localities but there’s a number of orange ladybirds within those records so it’s not unusual now for us to get an aggregation sent to us, and orange ladybirds were a species that were really quite a rarity.

Interviewer

This is a very beautiful insect isn’t it?

Helen Roy

It is absolutely exquisite, it is orange as its name suggests, but it has white spots and almost if you look at it it sort of almost has a sort of translucent edge to it. And it’s a mildew feeder, so unlike many of the other species we’ve been talking about that feed on other insects this is a mildew feeding ladybird and we do wonder whether there are several reasons why it might be increasing. One is that the warmer wetter weather might be increasing the mildews around so it’s got more to eat, it’s also beginning to feed on many different host plants, so the mildews that are occurring on many different types of plant, so it’s become a bit more generalist in terms of the habitats that it will occur, and that’s all for the benefit of it in terms of numbers.

Interviewer

We have some quite small ladybirds as well which don’t look like the traditional ladybird image, you know, they’re not red with black spots or orange with black spots or even orange with white spots, these will be new to a lot of people, certainly they were new to me and there was a big range of those really, really small things and you’ve mapped those as well.

Helen Roy

We have, and we know for sure that the maps that we produce for those inconspicuous ladybirds are likely to be incomplete because we think people are overlooking them, and we’d really like to get a much better picture, so when we do our next Atlas we know a lot more clearly where these little inconspicuous ones occur. And they are really stunning, they’re tiny, maybe a couple of millimetres, and often hairy which is really very lovely as well and so, you know, if someone’s out looking and they see a little tiny hairy brown beetle and if they look a bit closer and start to see some markings on it and it has short antennae then we’d be really interested to hear about it, because it’s very likely to be an inconspicuous ladybird.

Interviewer

We should talk I suppose about the involvement of people, because a huge amount of records have come in to make up this Atlas. How important have volunteers, observers been?

Helen Roy

Oh it’s been absolutely inspirational. So when we launched the online surveys, we’ve just been bombarded with people’s records and people’s questions and people’s interest and enthusiasm, and we’ve had tens of thousands of people contribute to this Atlas and that just feels absolutely fantastic that the nation’s got behind it and sent in their records and that data’s really high quality. We’re extremely excited by the response and we’re really hoping that people continue to get behind the ladybird survey and keep sending in their records, so our next Atlas is even more complete.

Interviewer

So you still want records, you still want to know about the distribution and changing habits of ladybirds.

Helen Roy

Absolutely. We want people to keep going with all their recording and it doesn’t matter if they sent a seven spot ladybird in from their garden before, please send that record in again, keep sending in the records on an annual basis or on a monthly basis, we don’t mind how often, we just want those records to come into us.

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